experiments in confined systems with different proportions of free and adsorbed gases. The results show that different adsorption capacities and non-synchronous desorption for alkane gas components are leading factors influencing chemical fractionation during the desorption process. Meanwhile, C /C and C /(C +C ) vary with 1 2 1 1 2 different proportions of adsorbed gases in the same adsorption matrix. Generally, isotope fractionation between the adsorbed and free phases during desorption follows the Rayleigh fractionation model. The linear correlations between proportions of adsorbed CH and isotope fractionation factors can be applied to predict the 4 proportions of adsorbed gases. Calculations show that on average 55% of hydrocarbon gases exist at adsorbed state in shale gas from Yanchang Formation of Ordos Basin.

Liu, S., Zhang, R., 2020. Anisotropic pore structure of shale and gas injection-induced nanopore alteration: A small- angle neutron scattering study. International Journal of Coal Geology 219, 103384.

http://www.sciencedirect.com/science/article/pii/S0166516219306652 Gas transport in the shale matrix is controlled by pore structure, which can ultimately influence natural gas in situ production potential and carbon sequestration in shale gas reservoirs. In this study, small-angle neutron scattering (SANS) measurements under methane and CO injections were employed to investigate two 2 Marcellus Shale thin section samples cut parallel and perpendicular to the bedding. Marcellus Shale nanopores show intrinsic anisotropy over the detected length scale of 5 - 2000 Å. Microscopic gas transport could be inhibited due to the decrease of accessible porosity with increasing gas pressure. The degree of inhibition may be higher for CO than for methane, and for the direction normal to the bedding than in the bedding direction. In 2 addition, under the condition of liquid CO , higher porosity reduction for the direction normal to the bedding 2 may insight into nanoscale anisotropic wettability in the shale matrix.

Liu, W.-W., Pan, J., Feng, X., Li, M., Xu, Y., Wang, F., Zhou, N.-Y., 2020. Evidences of aromatic degradation dominantly via the phenylacetic acid pathway in marine benthic Thermoprofundales. Environmental Microbiology 22, 329-342.

https://doi.org/10.1111/1462-2920.14850 Thermoprofundales (Marine Benthic Group D archaea, MBG-D) is a newly proposed archaeal order and widely distributed in global marine sediment, and the members in the order may play a vital role in carbon cycling. However, the lack of pure cultures of these oeganisms has hampered the recognition of their catabolic roles. Here, by constructing high-quality metagenome-assembled genomes (MAGs) of two new subgroups of Thermoprofundales from hydrothermal sediment and predicting their catabolic pathways, we here provide genomic evidences that Thermoprofundales are capable of degrading aromatics via the phenylacetic acid (PAA) pathway. Then, the gene sequences of phenylacetyl-CoA ligase (PCL), a key enzyme for the PAA pathway, were searched in reference genomes. The widespread distribution of PCL genes among 14.9% of archaea and 75.9% of Thermoprofundales further supports the importance of the PAA pathway in archaea, particularly in Thermoprofundales where no ring-cleavage dioxygenases were found. Two PCLs from Therm oprofundales in vitro MAGs, PCL and PCL , were able to convert PAA to phenylacetyl-CoA (PA-CoA) , M8-3 M10-15 demonstrating the involvement of Thermoprofundales in aromatics degradation through PAA via CoA activation. Their acid tolerance (pH 5 -7), high-optimum temperatures (60°C and 80°C), thermostability (stable at 60°C and 50°C for 48 h) and broad substrate s pectra imply that Thermoprofundales are capable of in situ transforming aromatics under extreme conditions. Together with the evidence of transcriptional activities for most genes related to the aromatics pathway in Thermoprofundales, these genomic, and biochemical evidences highlight the essential role of this ubiquitous and abundant archaeal order in the carbon cycle of marine sediments.

Liu, X.-Q., Li, M., Zhang, C., Fang, R., Zhong, N., Xue, Y., Zhou, Y., Jiang, W., Chen, X.-Y., 2020. Mechanistic insight into the optimal recovery efficiency of CBM in sub-bituminous coal through molecular simulation. Fuel 266, 117137.

http://www.sciencedirect.com/science/article/pii/S0016236120301320